Jack



R. B. JESTER JACK.

APPLICAHON FILED AUG.25, I9l9- 1,348,879. Patent d Aug- 10, 1920.

2 SHEETSSHEET I.

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IN VEN TOR ATTORNEY.

R. B. JESTER.

JACK. APPLICATION FILED AUG-25, F919- 7 1,348,879. Patented Aug. 10, 1920;

2 SHEETS-SHEET 2.

INVENTOR A TTORNE Y.

' jack.

UNITED STATES PATENT OFFICE.

RONALD B. JESTER, on NEW CUMBERLAND, WEST VIRGINIA.

JACK.

To all whom it may concern:

Be it known that I, RONALD B. JESTER, a citizen of the United States, residing at New Cumberlanchin the county of Hancock and State of Vest Virginia, have invented new and useful Improvements in Jacks, of which the following is a specification.

This invention relates to jacks, and more particularly to a aclr for use in connection with automobiles and for similar purposes.

One of the main objects of the invention is to provide a jack of simple and efficient construction which may be readily produced and supplied to the automobile trade at a relatively low cost. A further object is to provide a jack in which the number of parts is reduced to a minimum, and in which very simple and highly efiicient means is pro vided for raising and lowering the lifting bar. Further objects will appear from the detailed description.

In the drawings Figure 1 is.a side view of a jack constructed in accordance with my invention.

Fig. 2 is a central vertical sectional view, the lifting bar and operating means therefor being shown in elevation.

Fig. 8 is a fragmentary detail sectional view showing the lifting pawl and associated parts in elevation.

Fig. 4; is an enlarged detail side view of the lifting pawl and locking dog and associated parts.

Fig. 5 is asimilar view the relative positions of the parts being altered.

Fig. 6 is a fragmentary back view of the F" g. 7 is a detail of the pawl guiding and tripping pin. 7

Fig. 8 is a detail plan View of the pawl and dog operating spring.

Fig. 9 is a detail of the operating shaft.

The jack is provided with a base plate 1 formed integral with a standard 2 of rectangular cross section in which. is slidably mounted a lifting bar3 so as to be braced and guided by the standard during its operation... This lifting .bar is provided on its rearward side with a plurality of downwardly and rearwardly inclined teeth form ing a rack 4:. The 'bar is further provided, adjacent the lower end of itsfront face with an integral step or outwardly projecting element 5 which operates in a slot 6 through the front wall of the standard this element being specially adapted for engage- Specification of Letters Patent.

Application filed August 25, 1919.

Patented Aug. 10, 1920.

Serial No. 319,543.

ment beneath objects which are positioned so closely to the supporting surface as not to permit ready positioning of the plate or head 7 which may be secured on the upperend of the bar in any suitable or well known manner.

The rearward and side walls of the standard are extended outwardly and upwardly to provide a casing section 8 which cooperates with a similar section 9 secured'to the side walls of the standard to provide a casing or housing for inclosing the operating mechanism for the lifting bar. A shaft 10 is rockably supported by member 8 for 0s cillation about an axis extending transversely of the standard. This shaft is provided with an eccentric 11 provided at its inner side with a peripheral flange 12 which serves to prevent relative inward movement of a pawl 13 which is mounted upon this eccentric. Adjacent the outer face eccentric 11 the shaft is provided with a squared lug 14 which is secured in a corresponding opening in a plate 15 formed integrally with a socket member 16 adapted to receive the end portion of a suitable handle for reciprocating this member so as to cause oscillation of the shaft, it being understood that the sections 8 and 9 of the housing or casing are provided with alined slots for permitting this movement of the plate. As will be readily understood, rocking or oscillating of the shaft 10 serves to impart vertical reciprocation to the pawl 13.

The pawl 13 is adapted for engagement with the teeth of rack 4: with which it is normally held in engagement by a leaf spring 1'? which is secured by means of a screw 18, or in any other suitable manner, to the casing section 8. This spring is extended downwardly and inwardly beyond.

the screw 18 for engaging a locking dog 19 which is pivoted upon a pin" 20 secured through the sides of casing section 8. This dog acts to normally hold'the lifting bar '3 against downward movement, as will be .of the casing in position.

head 25 which serves to positively limit inward movement of the pin when initiallyinserted into the standard, the end element 23 being of such length that, when the head 25 is in contact with the outer face of a H boss 26 formed integral with upper section -9 ofthe casing through which the pin is tion to serving as a guiding element for the pawl also serves to secure the upper section When the pawl and the'parts associated therewith are positioned as in Fig. 3, by rocking shaft 10, the

lifting bar 3 may be readily raised, as will be clear from Fig. 2 of the drawings, the bar being raised the distance. of one tooth ofthe rack 4 foreach complete downward and outward movement of-the shaft.

As will be clear from Figs. 3 and 6, the shaft 10 is supported by the housing so as to be capable of axial movement therein. Normally, this shaft is so positioned that the pawl 13 engages the rack 4 so as to lift the bar 3 in the manner described. When it is desired to lower the rack, however, the socket 16 is rocked downwardly so as to slightly raise the pawl 13 and the bar 3, the

pawl 'being'raisedto such an extent as to clear the enlarged tripping element 23 of the pin .21, as in. Fig. .4. After the pawl has been thus raised,.the shaft 10 may he slid toward the left of the casing as considered in Fig. 3 of the drawings. When the shaft is moved into its extreme position toward the left of the casing, the pawl will ride upon the tripping element 23 so that it will exert but very little lifting effect upon the bar3, and will be moved out of'engagement with the rack when the socket 16 is rocked upwardly and inwardly so as to lower the pawl. IVith the shaft in this position, that is, moved into its extreme position toward theleft of the casing, when the socket is .rocked downwardly a cam element 27 which is formed on the shaft adjacent the inner face of eccentric 11 is brought into engagement with the upper portion of a tripping arm 28 formed integrally with looking dog 19. This serves to move the dog out of engagement with rack 4: of the bar 3, this movement of the dog into inoperative position taking place immediately subsequent to engagement of the rack and lifting pawl 13, as in Fig. 5'. This operation serves to lift the bar 3 the distance of approximately one-fourth of a tooth, after which the shaft 10 is rocked upwardly and inwardly so as to lower the pawl 13 and consequently the bar 3. As the pawl is lowered, it engages the tripping element 23 of the pin and is moved out of engagement with the rack. As the pawl approaches its lower-most position, the cam 27 is moved upwardly out of engagement with arm 28 thus releasing dog 19 which is moved into operative position and engages beneath the next tooth of the rack at above that tooth with which the dog was in engagement at the commencement of the lowering operation. This operation will be clear by reference to Fig. 5 in which the pawl 13 has been raised into such a position as to slightly elevate bar 3, the dog 19 being rocked outwardly out of engage ment with the rack 4 so as to be positioned for engagement beneath a succeeding tooth of the rack upon release of the arm 23 and movement of the pawl into inoperative position. WVith the parts in the position illustrated in Fig. 5, when the socket 1-6 is rocked upwardly and inwardly, the bar 3 is lowered' so as to permit the dog to engage beneath the tooth next above that with which it was formerly in engagement, after which the cam 27 is moved out of contact with arm 28, pawl 13 being then moved out of engage- -ment with rack 4, thus permitting the bar 3 to descend the distance of one tooth. By this construction, the lifting bar3 may be readily elevated and, by shifting the shaft .of extremelysimple construction which may be readily produced at small cost and may therefore be furnished to the automobile trade at such a price'as to justify its extensive use. I11 addition, the number of elements employedis' reduced to a minimum and complicated construction is avoided thusv producinga jack of simple, inexpensive, and highly efficient construction. In practice it may be found desirable to make slight changes in the construction and arrangement of the details of the device, and I intend to include all-such variations, as fall within the scope of the appended claims in this application in which a preferred form only of my invention is disclosed.

What I claim is: j

1. In a jack, alifting bar, an operating shaft adjustable into either one of two operative positions, and means associated with said shaft and controlled by the adjustment thereof for raising the bar when the shaft is in one position and lowering the bar when said shaft is in its other position.

2. In a jack, a lifting bar, an operating shaft adjustable into either one of two operative positions, and means associated with said shaft and controlled by the adjustment adjustment thereof for raising the bar when the shaft is in one position and lowering said bar when said shaft is in its other position. 7

l Inajack, a rack bar, a pawl normally in engagement with said bar, a retaining dog normally in engagement with the bar, means for reciprocating said pawl, said means being movable into either one of two operative positions relative to said dog, and means for moving the dog out of engagement with the bar and releasinglit and subsequently moving the pawl out of engagement with said bar when said reciprocating means is in one of its operative positions, said means 'moving the pawl out'of engagement with the bar during its down stroke when the reciprocatin'g'means is in said positionso as to permit step by step lowering of thebar.

5. In a jack, a rack bar, a rockable shaft, a pawl normally in engagement with said bar, connections between said pawl and shaft for reciprocating the pawl, a retaining dog normally in engagement with said bar, the shaft being adjustable into either one of two operative positions relative to said dog, means actuated by the shaft when in one position for moving the dog into inoperative position and releasing it, and means for moving the pawl out of engagement with the rack bar during its downward stroke subsequent to release of the dog. 7

6. In a jack, a rack bar, a rockable shaft, a pawl supported by said shaft so as to be reciprocated thereby and normally in engagement with said bar, a retaining dog normally in engagement with the bar, the shaft being adjustable into either one of two operative positions relative to the dog, means for preventing engagement of said pawl with the bar until the pawl approaches the limit of its upward travel and for moving the pawl out of engagement with the bar as it moves downwardly when the shaft is in one position, and means for moving the dog out of engagement with said bar and holding it in this position during downward travel of the pawl and then releasing said dog prior to movement of the pawl out of engagement with said bar, when the shaft is in said position.

7. In a jack, a rack bar, a retaining dog normally in engagement with said bar, an operating shaft adjustable into either one of two operative positions relative to said dog, a pawl carried by said shaft so as to be engagement of said pawl with the bar until the pawl approaches the limit of its up stroke and for moving said pawl out of engagement with the bar during its down stroke when the'shaft is in one position, and

means actuated by operation of the shaft for moving the dog out of engagement with the bar and for releasing it immediately prior to movement of the pawl out of engagement with the bar when the shaft is in said position to permit step by step lowering of said bar.

8. In a jack,"a rack bar, a retaining dog normally in engagement with said bar, an operating shaft mounted for axial adjustment into either one of two operative posi tions relative to said dog, a pawl normally in engagement with said bar, connections between said'pawl and the shaft for reciprocating the pawl, means for preventing engagement of the pawl with the bar until it approaches the limit of its up stroke and for moving the pawl out of engagement with said bar during its down stroke when the shaft is in one operative position, and means for moving the dog out of engagement with the bar as the pawl engages said bar and for retaining the dog in inoperative" position and then releasing it immediately prior to movement of said pawl out of engagement with the bar, when the shaft is in said position. I

9. In a jack, a rack bar, a retaining dog normally in engagement with said bar, an operating shaft, a pawl normally in engagement with the bar and eccentrically mounted on said shaft so as to be reciprocated thereby, a pawl tripping member positioned to be engaged by the pawl so as to prevent engagement of said pawl with the bar until it approaches the limit of its upstroke and move the pawl out "of engagement with said bar during its down stroke, said dog being provided with a tripping arm, and a tripping cam carried by the shaft for contact with said arm, the shaft being adjustable so as to optionally move said pawl and cam into and out of operating relation with the pawl tripping member and the tripping arm.

10. In a jack, a rack bar, a retaining dog normally in engagement with said bar, an operating shaft provided with an eccentric and a tripping cam, a pawl loosely mounted on said eccentric and normally in engagement with the bar, a tripping member positioned adjacent one side of the pawl and adapted when engaged thereby to prevent engagement of said pawl with the bar until it approaches the limit of its upstroke and to move the pawl out of engagement with the bar during its down stroke, and a tripping arm positioned at the same side of the pawl as said pawl tripping member and connected to said dog, for moving. the same out of engagement with the bar, said shaft. being axially adjustable so as to move the pawl and cam out; of or; into cooperating relation with the tripping member andlthe arm, said arm and the cam and eccentric-being-so related, as. to move the dog into inoperative position during/the upstroke of the pawl and; then; release said dog immediately prior tomovement: of the pawlout of engagement with said bar.

11. Ina jack, a standard, a rackbar slidable therein, an operating; shaft rockably a retainingdog supported by the standard and; normally in; engagement with the bar,

a pawl, tripping; member projecting. into the standard to; one-side oi the pawlxandso p0- sitioned as to prevent engagement of. the pawl; with the bar until it approaches .the limit. of itsup stroke andmove-thepawl out ofengagement of the bar during. its down stroke'when said pawl-is moved into cooperating relation with said member, said dog being provided with a tripping arm posit-ioned; at the same side of the pawl as the pawl;tripping member, and av trippingv cam carriedby the shaft the same side of the Lamaz pawl-as saidjarm, the saidshaft being axially supported? by the standard, a pawl eccentrica'lly mountedon the shaft so as tobe reciprocatedthereby and normally in engagement with said bar, apin extending across the standard beneath said pawl and provided with enlarged terminal elements, the pawl normally; operating between said terminal elementssoas to beheld thereby against aecidental lateral" displacement, one" of the terminal elements projecting into the standardand forminga pawl tripping member, a dog mounted in} the standard and normally inengagement with said; bar, said dog being provided with a, tripping arm positioned at the same sideoii the pawl as said pawltripping member, andratrippingcam carried by the shaft at thesameiside oi thepa-wlas said arm, said-shaft being axially adjustable so as to movethepawl and cam into orout of cooperatirierelation with the pawl tripping member and the tripping arm. 7

In testimony whereof I aflix my signature.

' R NA D B ES R- 

